Typically, a jet device comprises a nozzle and a needle mounted in an inner cavity of the nozzle. So far, the needle is generally with an elongated structure, the head of the needle is needle-like, and the needle is movable in the axial direction of the nozzle when an external force acts on, thereby adjusting the cross-section for water flow formed by the needle and the nozzle to regulate and control the nozzle jet flow. This type of jet device is widely used in hot water system for households, hotels and the hotel.
An example of a water mixing valve is disclosed in Chinese patent literature under No. 102086941B, the mixing valve includes a valve body provided with a cold water inlet on the valve body, the cold water inlet valve is in communication with a nozzle, said nozzle is provided with a needle valve for assisting the adjustment of cold water flow, and the cross-section area of water outlet of the nozzle is adjustable by screwing the needle valve in or out.
A further example of an adjustable jet device with multiple water sources is disclosed in Chinese patent literature under No. 102767210A, the jet device includes a jet body, a fluid working cavity and a needle, the fluid working cavity is disposed in the jet body, the front end of the fluid working cavity is provided with a nozzle, a needle is disposed on the extension line of the center line of the fluid working cavity, the end of the needle is provided with a needle stroke control means, wherein the needle can be moved in the axial direction of the nozzle under the control of the needle stroke control means to adjust the jetting flow of nozzle.
In practice, in order to reduce production costs for companies, the conventional needle (needle valve) for a hot water system is provided with an elongated structure, which is the same as that illustrated respectively in the drawings of above two patent literatures. However, after research, it is found that there are some defects for such elongated needle in practical use, i.e. the pressure put on the elongated needle in its radial direction is small when the pressure of the fluid flowing through the nozzle is small, which can meet the operation requirements. However, when the pressure of the fluid flowing through the nozzle is large or even very large and the fluid flow rate is instable, a larger and uniform pressure will occur and be put on the needle in its radial direction, i.e., in the elongation direction of the needle, then the different portions will have different radial pressure put thereon, which may cause a deviation of the water outlet of the needle, or cause a radial wobbling of the needle, thereby affecting the jetting effect of the nozzle.
If the needle with larger diameter is designed in order to solve the above problems, it will inevitably lead to an increase with weight of entire jet device and also the production costs correspondingly.